Range-finding devices, are commonly used to determine distances in such industries as agriculture, aviation and nautical. Sighting devices or aiming/targeting devices, such as laser guns, speed guns, or RF guns, are commonly used to aim at a particular target and select it from a plurality of targets in military and surveying applications, for example. Meanwhile, scanning devices, are used to scan objects for information, particularly for reading bar codes, and to optically map surfaces for quality control purposes.
Currently, range-finding devices are not used for scanning; sighting devices are not used for distance measurement or scanning and scanning devices are not used for distance measurement or aiming. Typically a range-finding device might incorporate a visual sighting system but the range-finding system and the sighting system of the device are two separate systems; the visual sighting system is not easily integrated into automated range-finding devices. Furthermore, visual sighting systems suffer from a number of problems that limit their usefulness, such as: (a) daylight only operation if no external target illumination is used, (b) the need for the user to look through the device-which in certain circumstances is undesirable (e.g. while driving or participating in other activities requiring vision), (c) susceptibility to sighting errors induced by diminished visual acuity of the user, (d) the need to ergonomically design the system to allow for use with, or without, corrective or other glasses. Also, such visual aiming systems are not easily integrated for use in automated ranging systems. Finally, typical scanning sources are usually limited to visual light transmitters.
It would be desirable therefore to have an optical system capable of performing all three functions of distance measurement, target acquisition and scanning. It would further be desirable to have an optical system capable of automated aiming/target identification and data acquisition. It would also be desirable to have an optical system that is not limited to visual light sources for use in scanning.
As shown in FIG. 4, a typical dual beam range-finding/sighting system 400 includes one beam path 418 for a transmit system and another beam path 428 for a receiving system. If system 400 includes a visual sighting system (in bold), it is typically a telescopic lens system including at least one lens 336 (and, in the case of non-inverting image types, a second lens 337) and its own beam path 448.
In the dual beam system 400 of FIG. 4, the transmit source 412 of the transmit system emits light that travels through the lens 416. This light becomes the collimated outbound beam 414. The outbound beam 414 hits a target (an object in space such as, for example, a building, a bar code on the building or an identification unit mounted on the building). The outbound beam is reflected from the target and returns to the receiving system of the dual beam system via beam path 428. As this reflected beam 424 passes through lens 426, it is refracted so that it comes to a focus at receiver 422. Meanwhile, the lens(es) 336, 337 of the scanning system (in bold) of system 400 are mounted near the optics 416, 426 of the ranging system and oriented so as to capture the intended field of view of the target 434 as well as the ranging transmit (outbound) and ranging receive (inbound) overlap fields.
FIG. 4 also shows a typical scanning system 450 that includes a scanning transmit source 452 that emits light which travels through beam scanning optic 455 then through lens 456. This light becomes outbound beam 458. Alternatively, beam scanning optic 455 may be placed so that light travels through lens 456 first before going through optic 455. The outbound beam 458 hits a target which usually includes some feature or pattern that, when light is scanned across its surface, creates a modulation of the light reflected from the surface as a return beam 468. The outbound beam 458 is usually moved relative to the target to produce the desired data stream on the return beam 468 reflected from the target. This scanning movement may be accomplished manually by a user physically moving the device relative to the target, mechanically or electro-optically (the optical beam 458 is directed in a repetitive pattern to the target using beam steering technology). Once the return beam 468 is reflected from the target, it passes through lens 466 where it is refracted to come to a focus at receiver 462. Once at receiver 462, the return beam 468 is converted into an electrical signal that can be analyzed using appropriate electronics and software.
The techniques of optical beam combination have been used in other optical systemsxe2x80x94such as microscopes that incorporate laser based micro-machining systems. However, the application of these techniques to distance measuring, range-finding, sighting and scanning systems for the purposes of reducing the overall system size, weight, complexity and cost would be desirable.
The integration of multiple range-finding, sighting and scanning technologies into one system will further make it desirable to render each component of the system, especially the optical system, as small as possible.